• Transactions of the Korean Society of Automotive Engineers
• /
• v.3 no.5
• /
• pp.24-29
• /
• 1995

A laser system and signal aquisition system to use a laser-induced fluorescence technique were arranged to measure NO concentration. To identify the NO fluorescence signal, verification of the fluorescence was performed through use of comparison of the signals taken both in a undoped and doped calibration flames. Finally, the spatial NO number densities in partially premixed flames were found as a function of fuel-tube equivalence ratio(${\phi}_c$) and overall equivalence ratio(${\phi}_o$).

• Korean Journal of Acupuncture
• /
• v.19 no.2
• /
• pp.97-117
• /
• 2002

Chiropractic is very similar to Oriental Medicine in philosophy on the cause of diseases and in utilization of spinal articulations for diagnosis and treatment. In this paper the spinal area used to treat liver dysfunction in S.O.T. technique, one of chiropractic techniques, was compared to the acupncture points used to cure the same conditions. Because both Oriental medicine and Chiropractic are dealing with autonomic nervous system in regulating abnormal conditions, also the innervation of spinal nerves to those areas was checked. The spinal area that S.O.T. technique utilizes to correct liver dysfunction is transverse processes of T8, which corresponds to B16. Acupncture points from this level down to T12/L1, which are B16, B17, B18, B19, B20, B21, B45, B46, B47, B48, B49, B50, GV6, GV7, GV8 and GV9, all have been applied to control liver function. Apparent discrepency exists in therapeutic areas for liver malfunction between the two natural healing arts. According to the neurology texts, liver is innervated by sympathetic fibers from the 7th-10th thoracic segments and by parasympathetic fibers from vagus nerve. Sympathetic afferent nerves from the liver reach the 7th-12th thoracic spinal cord segments. It can be said all the 7th-12th thoracic spinal cord segments are related to liver function. Therefore the areas used for liver dysfunction in both natural medicine are appropriately selected. However, B16, the Oriental medical equivalent of the main spinal area which is used for lowered liver function in C.M.R.T. Technique, is not utilized as frequent as in Oriental medicine.

• Therapeutic Science for Rehabilitation
• /
• v.5 no.2
• /
• pp.23-33
• /
• 2016

Objectives: The aim of this study was to investigate the association between cognitive function and upper extremity function in the elderly. The articles were analyzed based on patient, intervention, comparison, and outcome using the P.I.C.O. principle. Methods: We systematically examined papers from January, 2000 to November, 2015 published papers through the foreign journals which were Medline & Pubmed for three months. mainly used key words were elderly, dementia, Alzheimer's disease, Mild cognitive impairment, age-related, aging, cognitive, upper extremity function, hand function, hand-grip strength, grip force, complex motor function, bimanual, dexterity, UE performance, and coordination. Results: The number of discovered outcomes for association between cognitive function and upper extremity function in the elderly was 7; grip strength & sex are impact on manipulation object, 1. The results show that cognitive function is associated with upper extremity function in the elderly. Conclusion: This study is expected to help selecting intervention, assessment tools according to the individual's degree of cognitive level and upper extremity function. In future domestic research, variety assessment tools need to be used and more qualitative level experiment will be carried out.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.4
• /
• pp.179-187
• /
• 2001

In recent years, the switching source devices have the advantage of small, light and high reliability with the high-frequency. But, high-frequency switching has disclosed disadvantage of result from stress and turn-on and turn-off peak losses at the switching instant. Accordingly, in this paper propose ZVS-HB type high-frequency resonant DC/DC converter using soft switching technique (Zero-Voltage-Switching, Zero-Current-Switching) with safety operating of circuit at diving on inductive zone, through the circuit design example using the capacitor $C_3,\;C_4$ with soft switching function and division characteristic of resonant Capacitor C, $C_1,\;C_2$, and, the characteristic analysis of circuit is generally described using normalized parameters. Also, this paper certified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using MOSFET.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.5
• /
• pp.814-823
• /
• 2012

Fluctuation of light intensity from the keyhole becomes more significant in full penetration welding than partial penetration welding, since the plasma produced in the keyhole can escape from the rear side of the keyhole. The plasma optical radiation emitted during Nd:YAG laser welding of S45C steel samples has been detected with a Photodiode and analyzed under different process conditions. As the results, the BOP was performed for welding, behavior of plasma, spatter or plume was monitored to determine the reference signal. Then, random combination was made for comparison with the reference signal, which aimed at verifying reliability of the welding monitoring system that this study intended to develop.

• Tribology and Lubricants
• /
• v.26 no.2
• /
• pp.97-104
• /
• 2010

A new magnetoelastic technique of oil viscosity measurement, where the oil viscosity is estimated by frequency shift of natural oscillations of magnetoelastic ribbon, is implemented in this study. Laboratory tests of the detector prototype are performed for measurement of viscosity of base synthetic and mineral oils. It was found that measurement accuracy was better when damping factor was estimated in comparison with accuracy of frequency of damped oscillations. Thus the oil viscosity was calibrated as a function of number of pulses of the damped oscillations of magnetoelastic ribbon. Result generally showed that developed detector is promising for in line oil viscosity measurement in wide viscosity range from 10 cSt up to 600 cSt, while the viscosity measurement was relatively instable when the viscosity of test oil was over 400 cSt.

• Journal of Advanced Marine Engineering and Technology
• /
• v.38 no.5
• /
• pp.541-549
• /
• 2014

Horizontal axis tidal turbines are machinery inherited from the principle of wind turbines to enable the application of utilizing ocean's current energy. Its function does not differ from that of wind case, which is to convert fluid's kinetics energy to mechanical torque, therefore generates electricity. Since the ocean has been an enormous source of untapped power, tidal turbines have been being investigated recently to meet human's demand of energy with respect to environment friendly approach. This paper introduces a couple of turbine designs which are anticipated to have high performance. A comparison among recent works on the same topic is also made for validation.

• Structural Engineering and Mechanics
• /
• v.32 no.6
• /
• pp.741-754
• /
• 2009

Excessive cable vibrations are detrimental to cable-stayed bridges. Increasing the system damping of cables is a key solution to resolve this severe problem. Equations representing the dynamic characteristics of an inclined cable with a Deck-Anchored Damper (DAD) or with a Clipped Tuned Mass Dampers (CTMD) are reviewed. A theoretical comparison on the performance of cable vibration reduction between the cable-DAD system and the cable-CTMD systems is thoroughly discussed. Optimal system modal damping for the free vibration and transfer functions for the forced vibration for the two cabledamper systems are addressed and compared in detail. Design examples for these two different dampers are also provided.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 1997.11a
• /
• pp.154-161
• /
• 1997

Several studies have developed upward flame spread models which use somewhat different features. However, the models have not considered the transient effects of the igniter and the burning rate. Thus, the objective of this study is to examine a generalized upward flame spread model which includes these effects. We shall compare the results with results from simpler models used in the past in order to examine the importance of the simplifying assumptions. We compare these results using PMMA, and we also include experimental results for comparison. The results of the comparison indicate that flame velocity depends on the thermal properties of a material, the specific model for flame length and transient burning rate, as well as other variables including the heat flux by igniter and flame itself. The results from the generalized upward flame spread model can provide a prediction of flame velocity, flame and pyrolysis height, burnout time and position, and rate of energy output as a function of time.

• Structural Engineering and Mechanics
• /
• v.74 no.1
• /
• pp.83-90
• /
• 2020

Several classical and higher order plate theories were used to study the buckling of functionally graded material (FGM) plates. In the great majority of research, a power function is used to represent metal and ceramic material transverse distribution (P-FGM). Therefore, the effect of having other transverse variation of material properties on the buckling behavior of thick rectangular FGM plates was not properly addressed. In the present work, this effect is investigated using the Third order Shear Deformable Theory (TSDT) for the case of simply supported FGM plate. Both a sigmoid function and an exponential functions are used to represent the transverse gradual property variation. The plate governing equations are combined with a Navier type expanded solution of the unknown displacements to derive the buckling equation in terms of the pre-buckling in-plane loads. Finally, the critical in-plane load is calculated for the different buckling modes. The model is verified by a comparison of the calculated buckling loads with available published results of Al-SiC P-FGM plates. The conducted parametric study shows that manufacturing FGM plates with sigmoid variation of properties in the thickness direction increases the buckling load considerably. This improvement is found to be more significant for the case of thick plates than that of thin plates. Results also show that this stiffening-like effect of the sigmoid function profile is more evident for cases where the in-plane loads are applied along the shorter edge of the plate.